Grounds on which a candidate other than the returned candidate may be declared to have been elected

(1) If any person who has filed an election petition has, in addition to calling in question the election of the returned candidate, claims a declaration that he himself or any other candidate has been duly elected and the prescribed authority is of opinion- (a) that in fact the petitioner or such other candidate received a majority of the valid votes; or (b) that but for the votes obtained by the returned candidate by corrupt practices the petitioner or such other candidate would have obtained a majority of the valid votes, the prescribed authority shall after declaring the election of the returned candidate to be void declare the petitioner or such other candidate, as the case may be, to have been duly elected. (2) The decision of the prescribed authority shall be final.